Total parenteral nutrition in acute illness

Successful total parenteral nutrition in acute illness requires an appreciation of the pathophysiology of the illness and an understanding of the nutritional state of the patient, as well as a knowledge of the principles of total parenteral nutrition. Management of the acutely ill patient's general condition is essential prior to the introduction of nutritional support. A basic regimen which includes administration of 1-2g/kg/day of protein, and 8,400 kJ (2,000 kcal)/day of energy, part glucose and part lipid, together with all minerals, vitamins and zinc, in an appropriate amount of water, should be provided. Modifications to this regimen may be indicated to accommodate cardiac, respiratory, liver or renal failure. The questions of the optimum mix of carbohydrate and lipid, the ideal amount of protein and the correct mix of amino acids for a particular period in an individual patient's illness, are still debated. The fact that recent research supports many of the postulates of the Scandinavian pioneers of total parenteral nutrition suggests we may be returning to a correct approach.